Ville



(No Model.)

E; FL'INT.- Jr.

y PLUG POR BLEGTRIGAL SWITCH BUARDS N'o. 279,557. Patented June 19,1883.

WQW/@Jea 5m/anta?? wwf UNITED STATES PATENT OFFICE.

EDWARD ELINT, .IR.,'OE BOSTON, MASSACHUSETTS, ASSIGNOR, RY DIRECT AND MESNE ASSIGNMENTS, To IIIMSELE, CHARLES WILLIAMS, .IR.,-OE SOMER- vILLE, MASS., AND JOHN n. DUNRAR, OE SAN ANTONIO, TEX.

PLUGFOR ELECTRICAL SWITCH-BOARDS.

SPECIFICATION forming part of Letters Patent No. 279,557, dated June 19, 1883.

` Application led Novemher', 1882. (No model.)

To a/ZZ whom it may concern.-

Beit known that I, EDWARD FLINT, J r., of Boston, in the county of Suffolk and State of Massachusetts, have invented certain Improvements in Plugs for Switch-Boards orl Equivalent Connecting Devices, of which the following is a specification.

This invention relates to plugs for electrical switch-boards or to equivalent electrical con- 4Io necting devices, in which one or more movable metallic parts are held with a yielding pressure in contact With other metallic parts.

The invention has for its object to provide an improved construction whereby a reliable I 5 Contact is maintained; and to this end the invention consists in a plug or connecting device in which the metallic part or parts are supported by a body of soft or yielding vulcanized rubber, as I will now proceed to describe 2o and claim, I y

Of the accompanying drawings, forming a part of this specification, Figure l represents a side elevation of a switch-board plug embodying my invention. Fig. 2 represents a 2 5 section on line x Fig. l. Fig. 3 represents a Section on line y y, Fig. l. Fig. 4 represents a similar section, Showing a modication of form. Figs. 5, 6, and 7 represent other modiiications.` l

The same letters of reference indicate the same parts in all the figures.

In carrying out my invention I employ a body, a, of softor yielding vulcanized rubber, and place on the surface or surfaces thereof 3 5 one or more metallic strips, b, and the arrangement of the strips may be variously modified. For use in electrical -switch-boards having metallic strips, with perforations into Which a plug is to be inserted, I prefer the form shown 4o in Figs. l, 2, and 3, in which the body a is made in the form of a tube, and secured by a central metallic rod, c, to a handle, d, of insulating material. The strips b are in this instance out from a single piece, and bent to cover the n outer end of the body a and lie upon its surface. The ends of the strips are clamped between a slightly-tapered metallic block, e, which is Secured to the handle, and a ring, f,

which is driven over the block e, as shown. The rubber body a is of such thickness as to 5o cause the Strips b to bulge outwardly, so that when the plug is inserted in an orice in the switch-board the strips b will be pressed inwardly against-the rubber by the walls of the oriiice, the rubber being thus caused to press the strips closely against the walls of the orifice.

If desired, the rubber body a may be square in cross-section, as shown in Fig. 4.

rlwo metallic strips may be used, as in the 6o modification shown in Figs. 6 and 7, the rubber a' being a block interposed between and riveted to said strips, which are secured at their rear ends to a handle, d.

The rubber body may be made in the form of a larger tube, withthe strips b secured to its inner surface, as shown in Fig. 5. This modification is intended to receive a Vsolid metal rod or plug, but is Obviously an equivalent of the other forms, the soft rubber giv- 7o ing a yielding pressure to the strips.

I claim- 1. An electrical plug or connecting device having a body or piece of soft or yielding vulcanized'rubber, and one or more metal strips 75 secured to said body and receiving a yielding pressure therefrom, as set forth.

2. The improved plug composed of a body of soft or yielding vulcanized rubber, one or more metal strips placed upon said body and 8O receiving a yielding pressure therefrom, and a suitable stock or handle, as set forth.

3. The improved plug composed of the softrubber body a, the metal strips 6, laid upon said body, the slightly-tapered block e and 8 5 ring f, whereby the ends ofthestrips b are clamped, and a suitable handle, all constructed and arranged substantially as described.

In testimony whereof I have signed my name to this specification, in the presence of two sub- 9o scribing witnesses, this 1st day of November,

EDWARD FLIN'I, JR. lWitnesses:

A. L. WHITE,

ELLA M. -RICE'- 

